Writing tools
Install Notepad App
この無料オンライン ツールで JSON を瞬時にフォーマット、検証、美化します。エラーを修正し、JSON を圧縮し、数秒で読みやすさを向上させます。高速かつ安全。
Progressive Web App
We ship a web app manifest so browsers can offer “Install” or “Add to Home Screen”. Offline behavior depends on your browser cache; your data stays on-device unless you use features that explicitly sync.
After install, open Notepad.is from the icon for a focused, app-like shell with the same secure, local-first writing experience.
Desktop (Chrome, Edge)
Look for the install icon in the address bar or the browser menu → Install Notepad.is.
iPhone & iPad (Safari)
Tap the Share button, then Add to Home Screen.
Android (Chrome)
Menu (⋮) → Install app or Add to Home screen.
Related tools
Similar converters and utilities you can use next—still free and processed in your browser where applicable.